1. Field of the Invention
The present invention generally relates display systems, and more particularly to a holographic apparatus and method for multiplying the resolution of a display system.
2. Description of the Relevant Art
Display devices (e.g., computer monitors, television screen, and LCD panels) typically produce an image by selectively activating an array of pixels. The pixels each represent a fractional portion of the image which, when combined with the other pixels of the display, produce the full image. The resolution of the image refers to the number of pixels used to produce the image. In general, the more pixels which are used to create an image the better the image quality. For example, a computer display screen operating at a resolution of 1024xc3x97768 pixels produces images which tend to have observably better image quality than a similarly sized computer display screen operating at a resolution of 800xc3x97600 pixels.
The effect of a display""s resolution on image quality also tends to become more noticeable as the surface area of the display screen increases. For example, a 17 inch display screen operating at a resolution of 800xc3x97600 pixels will produce images that appear sharper than a 50 inch display screen operating at the same resolution at the same viewing distance. As the size of the display screen increases, without any change in the resolution of the screen, the individual pixels of the display must be spaced further apart to fill up the increased area of the display. This tends to cause the image to appear less sharp, especially to observers close to the display.
As technology advances there is an ever-increasing desire to increase the resolution of display devices. However, increasing the number of pixels of a display devices may be difficult and often cause the display to be significantly more expensive than lower resolution devices. It is therefore desirable to develop a method of increasing the resolution of a display device without having to alter the number of pixels present in the display device.
The problems outlined above are n large part solved by a system and method for display resolution multiplication. In one embodiment, a system is provided that includes a display device comprising a plurality of light emitting pixels and at least a first optical element that contains at least a first hologram. A first pixel of the display emits first and second light in first and second directions, respectively. The first and second directions define a non-zero angle therebetween. The first optical element is positioned to receive the first light, and in response thereto, the first optical element diffracts the first light. The diffracted first light emerges from the first optical element in a direction substantially parallel to the second direction of the second light emitted from the first pixel. In one embodiment, the first optical element effectively increases the perceived size of the first pixel as seen by a viewer thereof.
In another embodiment, the system describe above also includes second and third optical elements. The second optical element is positioned to receive the first diffracted light while the third optical element is positioned to receive the second light. The second optical element operates in an active state or an inactive state. The second optical element transmits the diffracted first light without substantial alteration when the second optical element operates in the active state. The second optical element extinguishes the diffracted first light when the second optical element operates in the active state. In the active state, third optical element transmits the second light without substantial alteration. In the inactive state, the third optical element extinguishes the second light. The third optical element is configured to be active when the second optical element is inactive, and wherein the third optical element is configured to be inactive when the second optical element is active. In one embodiment, the states of second and third optical elements can be switched at the refresh rate of the display thereby effectively doubling the number of pixels seen by a viewer.
In one embodiment, the second and third optical elements contain second and third holograms, respectively. The second and third holograms may be recorded in a medium that includes a monomer dipentaerythritol hydroxypentaacrylate, a liquid crystal, a cross-linking monomer, a coinitiator, and a photoinitiator dye.